As the Crash dump suggests, It's the problem with the progressDialog which initiates in the onPreExecute() method. But in your doInBackground() method starts an activity on some condition without dismissing the progressDialog. This leads to Window Leakage shown in the crash dump.

doInBackground() should be used to do the networking or other harder tasks. UI related API's should not be called inside this method as this method runs on different thread(Not on Main GUI thread). So I suggest you to move the code that starts the new activity to onPostExecute() method and the progressDialog should be dismissed before launching the new activity.